Sounds like identity theft just waiting to happen. What else did they ask for? NI number, date of birth, previous names. Some schools do ask for this but really it's a bit risky and unnecessary until interview.

I'd be very hesitant about sharing any of that before I'd signed a contract.
Check out the school first.
The only things they need to know pre-interview are your credentials, citizenship, age - those are what can interfere with their ability to get a residence or work visa.
There are cases of scammers posing as schools in order to gather info for id theft. Proceed cautiously and make sure you're dealing with an actual reputed school.